Quantitative elemental mapping of granulite‐facies monazite: textural insights and implications for petrochronology

Texturally complex monazite grains contained in two granulite‐facies pelitic migmatites from south‐ ern Baffin Island, Arctic Canada, were mapped by laser ablation‐inductively coupled plasma‐mass spectrometry (using spot sizes ≤ 5 µm) to quantitatively determine the spatial variation in trace el‐ ement chemistry (with up to 1883 analyses per grain). The maps highlight the chemical complexity of monazite grains that have experienced multiple episodes of growth, resorption and chemical mod‐ ification by dissolution‐precipitation during high‐grade metamorphism. Following detailed chemical characterisation of monazite compositional zones, a related U–Pb dataset is re‐interpreted, allow‐ ing petrologically‐significant ages to be extracted from a continuum of concordant data. Synthesis of these data with pseudosection modelling of prograde and peak conditions allows for the tem‐ poral evolution of monazite …